Burglar-alarm.



PATENTED MAY 8 W. N. FAWGETT.

BURGLAR ALARM.

APPLICATION FILED MAY19,1905.

UNITED STATES PATENT OFFICE.

WVILLIAM N. FAVVOETT, OF NE YORK, N. Y., ASSIGNOR OF ONE-THIRD TO MORRISBERNHARD AND ONE-THIRD TO MARCUS BURCKHEIMER,

OF NEW YORK, N. Y.

BU RGLAR-ALARIVI.

Specification of Letters Patent.

ratented May 8, 1906.

To all whom it may concern:

Be it known that I, WILLIAM N. FAWCETT, a citizen of the United States,residing at the city of New York, in the borough of Brooklyn, county ofKings, State of New York, have invented certain new and usefulImprovements in Burglar-Alarms, of which the following is aspecification.

The object of my invention is to provide a new and improvedburglar-alarm which is simple in construction, reliable and eiiective,and permits cutting out any closure without rendering the entire systeminoperative and by means of which the break in the line can readily bediscovered.

In the accompanying drawing my improved burglar-alarm is showndiagrammatically.

I have illustrated my burglar-alarm as applied on three doors A, A and Abut it may as well be applied on more or less or on other closures or inwalls, 620. I have also shown two sets of wiring, one in full lines andthe other in broken lines, although only one set may be used, two,however, being pre ferred for reasons that will appear later on. Agravity-battery B is used for the closed circuits, and an ordinarybattery C, such as a Le Clanche or dry cell, is provided for the opencircuit.

The battery C is connected with an electric bell D, and its terminalsare connected by the wires a and b with the two spring-contacts E, aswitch F being interposed in the wire or conductor a. The electromagnetF is in the circuit of the closed-circuit line and is fixed on aninclined support G. Its pivoted armature H can thus drop away bygravity, and when this armature drops or swings down the weightedprojecting arm J on the armature snaps in between the twospring-contacts E in the manner of a knife-switch, thus closing thecircuit of the open-circuit line C D b E F 0. Thus when the switch F isclosed and the circuit of the closed-circuit line is broken and themagnet F releases its armature the weighted arm J swings down and closesthe circuit of the local or bell battery and the bell D is sounded.

In each door A A A there are four springcontacts K, L, M, and N, fromwhich the wires cl and e extend over the door-that is, within thepaneling the ends of the wire (1 being connected with thespring-contacts K and M and the ends of the wire a with the contacts Land N. The fixed contacts K are connected with one pole of the magnet Fby a wire f, and the fixed contacts L are connected by a wire 9 with theother pole of the magnet F. The fixed contacts M and N are connected bythe wires h and m, respectively, with the poles of the battery B. Aslong as the circuit through the wires d c in the door, thespring-contacts K L M N, and the wires f g h m, and the battery B remainunbroken the armature H remains attracted, and the circuit of the localor bell battery remains open, and consequently the bell D is notsounded; but as soon as the circuit through the wires in the door, thecontacts, the battery B, and the magnet F is broken the armature I-Idrops and the local or bell battery circuit is closed, and the bell D issounded.

When more than one door or closure is to be included in the line, thewiring in each door is the same as described; but the outer or fixedcontact of one end of the wiring of one door is connected with theopposite end of the wiring in the next door, as represented by the wires(1 e d e", and the battery B connects with the outer ends of the wiringin the last door, as shown. For the purpose of discovering which doorgives the alarm I provide six switches, (marked, respectively, 0 O P P RR the contact-button of each switch being connected with the lever ofthe adjacent one, as represented by the wires 0 0 p 12 the contactbuttons of the last switches being connected with the terminals of thebattery B, and the lever of each switch being connected with thecorresponding wiring of one door, respectively, as represented by thewires i If s s and w 10 respectively. The switches O O P I R arenormally open, and the circuit through any doorfor example, A will be asfollows: from one terminal of the battery B through the wire m throughthe wiring e of the door A the wire 6 to the wiring e of the door A thewire a, the wiring e of the door A, the wire 9, the magnet F, the wiref, the wiring (Z of the door A, the wire d, the wiring d of the door Athe wire (1 the wiring (Z of the door A and the wire it to the otherterminal of the battery B, and in like manner for any more doors orclosures. If the door A for example, is opened or a panel cut, thiscircuit, as described above, is broken, and the bell D is sounded, asdescribed above. It now remains to discover at which door or by whichdoor the circuit was broken. If now the switches O O P P R R are allclosed and the armature H is raised, it will be held in place as thecircuit of the battery B remains closed as follows: from one teiminal ofthe battery B through the wire m, the wiring e in the door A which isintact, the wire w closed switches R P 0 the wire t g, the magnet F, thewire f, the wire t, the closed switches O P R back to the battery. Ifthe switches R R areopened, this will not break this circuit, as itremains closed from the battery B, the wire 'm, the wiring e of the doorA which is intact, the wire W, the closed switches P 0 the wires t g,the magnet F, the wires f t, the closed switches P O, the wire w, thewiring d of the door A back to the battery. If the switches R R remainopen and the switches O O are also opened, the circuit remains unbrokenas follows: from the battery B, wire m, the wiring of the door A whichis intact, the wire W, the closed switch P, the wire 8 the wiring e ofthe door A, which is intact, the wire 9, magnet F, wire f, the wiring dof the door A, the wire 8, the closed switch P, the wire w, the wiring(Z of the door A which is intact, and the wire it back to the battery.If now the switches P or P are opened, the circuit is broken and thebell is sounded, as the ar mature I-I drops as soon as either switch P Pis opened, thus indicating that the break is in the door connected withthe switches P P, so that whenever an alarm is sounded it is onlynecessary to close all the switches O O P P R R and then open themsuccessively, and as soon as a switch connected with the door at whichthe circuit is broken is opened the alarm will be sounded. If thewirings d and e are brought in contact in tampering withany door, thecircuit will also be broken, as thereby a short circuit is formed whichcuts out the connection with the magnet F, and the armature of thelatter drops. To discover any tampering with a door, &c., byshort-circuiting, the two wirings d e are required; but for giving by asignal by mere breaking of the closed-circuit line the wire (1 or thewiring 6 will suffice, of

course,'with its corresponding set of switches O P R or O P R If thewiring 6 only is used, the switches O P R can be dispensed with, and thebattery B is connected, as

shown by the dotted line S, and the connection r is omitted. If, on theother hand, the wiringd only is used, the connection S (shown in dottedlines) is made and the connection 9" is dispensed with, as are also theswitches O P R The circuits and the efiiects of the opening and closingswitches remain practically the same as previously described. If thecircuit in any door or other closure is broken, this door can be readilycut out by means of its switch or switches without interfering in anyway with the balance of the line, which remains operative.

Having described my invention, what I claim as new, and desire to secureby Letters Patent, is

1. In a burglar alarm, the combination with a battery and electromagnet,and a circuit including the battery and the magnet, of separate wiringfor one or more separate closures included within said circuit, and aseparate switch for each closure, which switches serve for closing oropening the circuits of said closures, and means operated by said ma netfor closing a local battery,.substantialIy as set forth.

2. In a burglaralarm, the combination with a battery and anelectromagnet, and a circuit, in which circuit the battery andelectromagnet are included, of two separate wirings'for a closure, whichseparate wirings are included in said circuit, and a separate switch foreach wiring of each closure, which switches serve for closing or openingthe circuits of said closure and means operated by said magnet forclosing a local circuit, substantially as set forth.

3. In a burglaralarm, the combination with a battery and anelectromagnet, and a circuit in which the battery and magnet areincluded, two separate wirings for a closure, which separate wirings areboth in said circuit, and a separate switch for each wiring of saidclosure, which switches serve for closing or opening the circuits ofsaid closure, and means operated by said magnet for closing a localbattery, substantially as set forth.

4. In a burglaralarm, the combination with a battery and electromagnet,and a circuit including the battery and the magnet, of two independentwirings for each of a series of closures, two switches for each closure,one switch of each pair being connected with one wiring of the closure,and the other switch of the pair being connected with the other wiringof the closure, and the circuit of both wirings of the closures beingwithin the circuit of the aforesaid battery, and means operated by saidelectromagnet for closing a local circuit, substantially as set forth. 7

In testimony whereof I have signed my name to this specification in thepresence 'of two subscribing witnesses.

WILLIAM N. FAWOETT.

IIO

